The composition of the present invention is related to a quaternary ammonium salt detergent and the use of such quaternary ammonium salt detergents in a fuel composition to reduce diesel injector deposits and remove or clean up existing deposits on the diesel injectors.
It is well known that liquid fuel contains components that can degrade during engine operation and form deposits. These deposits can lead to incomplete combustion of the fuel resulting in higher emission and poorer fuel economy. Fuel additives, such as detergents, are well known additives in liquid fuels to help with control or minimize deposit formation. As the dynamics and mechanics of an engine continual advance, the requirements of the fuel must evolve to keep up with these engine advancements. For example, today's engines have injector system that have smaller tolerances and operate at higher pressure to enhance fuel spray to the compression or combustion chamber. Deposit prevention and deposit reduction in these new engines has become critical to optimal operation of today's engines. Advancements in fuel additive technology, such as detergents, have enabled the fuel to keep up with these engine advancements. Therefore, there is a need for detergent capable of providing acceptable performance in a liquid fuel to promote optimal operation of today's engines.
U.S. Pat. No. 5,000,792 discloses polyesteramine detergent obtainable by reacting 2 parts of polyhydroxycarboxylic acids with 1 part of dialkylenetriamine.
U.S. Pat. No. 4,171,959 discloses a motor fuel composition containing quaternary ammonium salts of a succinimide. The quaternary ammonium salt has a counterion of a halide, a sulphonate or a carboxylate.
U.S. Pat. Nos. 4,338,206 and 4,326,973 discloses fuel compositions containing a quaternary ammonium salt of a succinimide, wherein the ammonium ion is heterocyclic aromatic (pyridinium ion).
U.S. Pat. No. 4,108,858 discloses a fuel or lubricating oil composition containing a C2 to C4 polyolefin with a Mw of 800 to 1400 salted with a pyridinium salt.
U.S. Pat. No. 5,254,138 discloses a fuel composition containing a reaction product of a polyalkyl succinic anhydride with a polyamino hydroxyalkyl quaternary ammonium salt.
U.S. Pat. No. 4,056,531 discloses a lubricating oil or fuel containing a quaternary ammonium salt of a hydrocarbon with a Mw of 350 to 3000 bonded to triethylenediamine. The quaternary ammonium salt counterion is selected from halides, phosphates, alkylphosphates, dialkylphosphates, borates, alkylborates, nitrites, nitrates, carbonates, bicarbonates, alkanoates, and O,O-dialkyldihtiophosphates.
U.S. Pat. No. 4,248,719 discloses a fuel or lubricating oil containing a quaternary ammonium salt of a succinimide with a monocarboxylic acid ester. U.S. Pat. No. 4,248,719 does not teach, suggest or otherwise disclose low sulphur fuels, presence of fluidisers etc. Example 1 teaches polyisobutylene succinimide with DMAPA as the amine. The succinimide is then reacted with a salicylate.
U.S. Pat. Nos. 4,253,980 and 4,306,070 disclose a fuel composition containing a quaternary ammonium salt of an ester-lactone.
U.S. Pat. No. 3,778,371 discloses a lubricating oil or fuel containing a quaternary ammonium salt of a hydrocarbon with a Mw of 350 to 3000; and the remaining groups to the quaternary nitrogen are selected from the group of C1 to C20 alkyl, C2 to C8 hydroxyalkyl, C2 to C20 alkenyl or cyclic groups.
US 2011/0302828 to Fang et al., published Dec. 15, 2011 discloses a diesel fuel composition containing diesel fuel additive having a number average molecular weight of 500 to 10,000, wherein less than 25 wt % of the additive has a molecular weight of 400 or less.
The present invention, therefore, promotes optimal engine operation, that is, increased fuel economy, better vehicle drivability, reduced emissions and less engine maintenance by reducing, minimizing and controlling deposit formation.